Railroad crossings typically have a crossing gate and various warning indicia. Desirably warning is provided by mounting warning lights, signs, and the like on a cantilever mechanism connected to the support for the crossing gate. In order to be able to effectively service these lights, a ladder is typically provided on the support structure, having the bottom rung thereof spaced a large distance from the ground so as to discouraged unauthorized users from climbing up the ladder. However that poses a safety problem for authorized people when they wish to access the cantilever structure, warning lights, and the like.
According to the present invention, a ladder assembly is provided particularly for use with a crossing gate support in which a second ladder is slidable with respect to the stationary ladder, and can be moved from a position well above the ground to a position where it is supported by the ground, at an angle, so that an authorized person may readily climb up it to repair the warning lights or other structures on the cantilever arm, or otherwise associated with the crossing gate support. Because of the particular construction of the movable ladder, it can be locked in place. The ladder assembly according to the present invention thus provides safety for authorized users, while retarding access by unauthorized users to the same extent as is provided in conventional railroad crossing supports.
According to one aspect of the present invention a ladder assembly is provided comprising the following components: A first, stationary, ladder having first and second side rails, a bottom rung, and a top rung. The first ladder mounted so that the bottom rung is spaced from a ground or floor surface. A second movable, ladder having first and second side rails and a plurality of rungs, a top end, and a bottom end. Means for movably mounting the second ladder adjacent the top end thereof for movement along the stationary ladder from a first position in which the bottom end is spaced from the ground or floor surface, and a second position in which the bottom end engages the ground or floor surface. Means for pivotally mounting the second ladder to the mounting means for pivotal movement about a generally horizontal axis so that the bottom end of the second ladder is movable horizontally toward and away from the first ladder. And, means for retaining the bottom end of the second ladder in a position horizontally adjacent the first ladder.
The means for movably mounting the second ladder adjacent the top end thereof may comprise first and second slides each having a first ladder side rail receiving recess therein, and the pivotally mounting means may mount the side rails of the second ladder to the first and second slides. The slides can have almost any configuration, but it is particularly desirable to have the stationary ladder side rails as I beams, each having a generally T-shaped portion which is received within a T-shaped recess in each of the slides. A pivot pin, or one of the ladder rungs, may connect each side rail of the second ladder to a slide.
The retaining means may comprise at least one plate mounted to the first ladder and having at least one projection thereon which can releasably hold a portion of the second ladder, as for example passing through a slot in a lock bracket on the second ladder. The projection on the retaining means plate may include an opening for receipt of a padlock hasp, particularly when the first ladder is mounted to a support for a railroad crossing gate and warning structure. The retaining means also may comprise means for stopping movement of the movable mounting means. For ease of construction the second ladder also preferably has side rails each having an I-shape in cross-section.
According to another aspect of the present invention a method of gaining access to a stationary ladder mounted on a stationary support extending from a ground or floor having a bottom rung spaced from the ground or floor, and using a second ladder shorter than the first ladder, is provided. The method comprises the following steps: (a) Sliding the second ladder downwardly with respect to the first ladder so that a bottom portion of the second ladder engages the ground or floor. And, (b) moving the bottom portion of the second ladder horizontally away from the first ladder, and with the bottom portion thereof in contact with the ground or floor, while a top portion of the second ladder remains in operative contact with the first ladder. There may also be the further step, prior to step (a), of (c) detaching the second ladder bottom portion from the first ladder. The first ladder is typically stationarily mounted on a railroad crossing gate and signalling assembly support, and the method comprises the further step of unlocking a padlock prior to step (c) to allow detachment of the second ladder from the first ladder.
According to still another aspect of the present invention a railroad crossing and ladder assembly is provided comprising: A support for a railroad crossing gate and warning structure. A first ladder having a first length, first and second side rails, and a plurality of rungs extending between the side rails, the first ladder mounted to the support. A second ladder having a second length, less than the first length, first and second side rails and a plurality of rungs extending between the side rails. And, the second ladder mounted for sliding movement with respect to the first ladder, and for pivotal movement with respect to the first ladder.
The assembly typically further comprises first and second retaining plates mounted to the first and second ladders, respectively, to releasably hold the second ladder to the first ladder precluding relative pivotal movement therebetween, the retaining plates including openings therein for receipt of a padlock or the like to lock them together. Typically both the first and second ladder side rails have I-shaped cross-sections.
It is the primary object of the present invention to provide a simple yet effective ladder assembly, particularly for a railroad crossing structure, and a method of gaining access to a stationary ladder. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.